Why Screen Reader did not work on progress bar

Hi,

I am working on banking app, and testing on Samsung s5e and s10e;
We’d like to fully support “talkback” or “screen reader” functions for users, but just found that the “progress bar” will not be announced/focused when it is showed, so the user will not know it is processing. But it did work on stock android devices. We did need it announced “Loading, Progress bar” for any process which takes 3-5 seconds.

And It is not only happened on our app, but also other apps, including google’s apps.
We need to sent extra accessibilityEvent to trigger it announces “Loading, Progressbar”.

I was wondering if OneUI cut if off for some special purpose? and if it is possible to fix it for future release?

thanks,
Vincent